Casting machine



Jun11,1929. POLAK' 1,717,254

CASTING MACHINE Filed Aug. s. 192e z sneets-snet l fri- 5.1

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CASTING MACHINE Filed Aug. 8, 1928 2 Sheets-Sheet 2 55 a spring f such that it normally Patented June 11 1929.

1,717,254 IUNITED ,STATESV PATENT OFFICE.

Jos'izi" roLAx, or rmeun, czEcnosLovA CASTING MACHINE.

. Application illcd Augusta,

. This invention relates to a casting machine in which thc molten metal is forced out of a cylinder by means of a sliding piston directly into thel moulds. The invention consists in this, that the plunger is made removable from the Cylinder, for. enabling the latter to be filled, while the piston forming the bottom of the cylinder, on which the molten` metal poured into the cylinder rests, on the one hand 10,normally closes the connecting assagesbetween the interior of the vcy in er 'and the moulds lying directly next to it land on the other hand, when'ex'erting the casting pressure, rests on'the bottom of the cylinder and 15 finally, after the casting operation has been completed and the plunger ,has been with'- drawn, ej cts' the remaining metal outof the cylinder, at the' same time separating the runner in the mould from the vrest of the metal.

Owing to this arrangement it is possible to cast with metals having a high melting point since the bottom piston which rests on the bottom of the cylinder enables a great pressure to be exerted on the metal resting on it.. An important feature is that' ith this machine rom the time of pourin he metal into the cylinder up tothe introduction rof the plunger into the latter and the displacement of the plunger the molten metal partly solidi- 30. fies in its .outer layer. Owing to this,'wl1en the casting pressure is applied, the artly solidilied layer formed around the liqui metal core must -first be broken through in order to allow the viscous metal to enter the casting .35 passages.

In the accompanying drawings two constructional examples of the moulding machine are shown, Fig. l being a vertical section through one constructional form, Fig. E?.k a

40 vertical section through the second constructional form and Figs. 3 and .4 showing the plunger and the bottom piston in different operative positions in the cylinder of the second constructional form. In the various figv ures similar constructional parts bear similar reference letters.

In the constructonal form shown in Fig. 1 the moulds d, e are adapted to be brought up from the side to a cylinder a which is open at the top, for introducing 'the projections on the moulds, which are provided with the passages Z, into corresponding holes m in the wall of the cylinder, in which they littightly. In the cylinder a a vpiston c is supported by shuts oi the the cylinderwall or thepassage Z hole m 11 l l u ing medium,

Hssun l from the interior of the cylinder. The piston lrod of the piston c is pivotally attached to a pivoted lever yg so that the piston c can either be lowered to the bottom of the cylinder or by moving the lever upwards can eject the remainder of the meta out of the cylinder a after the casting operation is completed, at the same time separating the runner which has solidified in thel passage Z from the metal remaining in the cylinder.

The plunger b is ixed to the transverse head piece p which is guided by rods n. The latter are connected by a transverse head piece 'i to the rod of the pistonj to which motion is imparted in the cylinder lc by a controlled driving medium.'

The machine operates in the following manner:

After the moulds 'have been brought up against the cylinder a (see Fig. 1 to the left) the cylinder is lled with the requisitev amount of molten metal, the supported piston c closing the inner opening of the passages Z. On the piston 7 being moved downwards inthe cylinder/l: by means of the controlled driving the plunger b will directly and the piston c indirectly follow this motion.

until the piston c rests on the bottom of the4 cylinder a. During this part of the operation and during the subsequent downward motion of the plunger b a thin outer layer of the. 1'nolten metal partially soldifies, so that during the subsequent application of pres sure by the plunger b such a ed on the metalthat the soli iied outer layer is broken through and the metal surrounded y by it enters the passages Z and the moulds d, e. Thepistonisthereupon moved in the opposite direction for the purpose of raising the plunger b out of the cylinder a, and the piston c, which moves upwards in the same direction through the action of the spring f, again shuts oil the inner opening of the passage-Z, at the same time separating therunner which solidifies in the passage l from the metal remaining in the cylinder, after which, by actu ating the lever g, the remaining metal' is completely ejected from the cylinder.

The'constructional form shown in Figs. 2, 3 and 4 differs from that described above in this, that the piston maining metal out of the cylinder already rests on the bottom of the cylinder, when the molten metal is being introduced into the latter, and remains in that position during the whole of the casting operation, By' being ressure is exert.-

used fer ejecting the relie opposite the casting Ving which motion the manner described above.

turned about its axis the bottom piston stablishes' the connection .between the casting passages which are otherwise shut oit by it and the interior of the cylinder. This has the advantage that, during the casting operation, only the plunger has to be axially displaced inthe cylinderbut need no longer be guided with a sliding tit as it only comes in contact with the metal when athin layer of the surface of the latter has become relatively solid.

In contradistinction to the constructional form shown in Fig. 1 the piston crests on the bottom of the cylinder a while the latter is being filled and during the casting operation. The piston c is provided at certainplaces with grooves c rising fromthe edge of the piston towards the centre.

The rod s of the piston o extends through the transverse head piece i and is provided with an arm 1' by means of .which it can be turned. The rod s is further provided with a driving member o which, when inacertain position, can pass through, the slott in the transverse head piece Z or, on the ro'd s being turned by means of the arm r, rests across the slot t in the transverse head piece i so that the transverse head piece in its upward motion carries the rod s with it.

lThis machine operates4 in the following manner:

After the moulds d, e have been brought up. against the cylinder a the latter is filled" wlth molten metal while the plunger b is in the position shown in Fig. 2. The piston c closes the casting passages Z by means of the cylindrical parts of its periphery lying between the grooves c. o

The plunger b is thereupon moved downwards Vin the manner slot t in the transverse head piece z' is pushed over the driving member 0 on the rod s. The rod s and with it the piston c is thereupon turned at the suitable moment by means of the lever r or by means of any suitable mechanism in such a manner that the grooves c in the piston c will passages Z. The drivmg member o on the rod s will then lie across the slot t in the transverse head piece z'.

The plunger b during its further motion will produce a pressure in the column of metal so that nallyl the liquid metal core will break from thesolidiiied thin outer layer and be forced into the moulds d, e. After the casting operation has been completed the plunger ,o moves back again in the At the same time the transverse head piece i by means of the driving member o, which rests across it, carries the piston c along with it, whereby the runner in the passage Z is separated from the metal remaining in the cylinder and the latter is ejected from the cylinder. The rod s of the piston c is thereupon turned in such a manner that its driving member o can pass already described, durthrough the slot. tV in the transverse head piece z' under the action of gravity on the piston and the rod, whereby the piston c is again brought into a position on the bottom of the cylinder in which the casting passages Z are again shut oli from the interior of the cylinder. s

During the pressing operation, therefore, the piston c only makes a small rotary. motion.

As will be seen rom' the drawing, the plunger b may haveits' end surface formed so as to correspond to the piston c. The end surface of the plunger b is therefore provided with ribs ZJ inclined downwards towards the middle. When the piston cis in the casting position (Fig. 3), channels are formed by the opposingend surfaces of the plunger Z) and the piston @which directly face the casting passages Z. This arrangement allows the metal to pass more rapidly from vthe cylinder to the moulds.

'What I claim is: 1. A casting machine comprising in combination a cylinder capable of being filled with molten metal, lateral openings in the walls of the cylinder, a plurality of moulds capable of being moved so as to bring against-the said lateral openings, a plunger capable of sliding axiallyin the cylinder for producing the casting pressure and ofbeing Iso their gates up Withdrawn from the'cylinder while the molten metal and of ejecting the superfluous metal remaining in the cylinder after the completion of the castin operation, as and for the n purpose set forth.

2. A casting machine comprising in combination a cylinder capable of being iilled with molten metal, lateral openings in the walls of the cylinder, a plurality of moulds capable of being moved so as to bring their gates up against the said lateral openings, a plunger capable of sliding axially in the cylinder for producing the cast-ing pressure, controlled means for withdrawing the plunger from the cylinder for enabling the latter to be filled with the molten metal and a. piston capable of sliding in the cylinder, of shutting oil'l the openings in the cylinder walls during the introduction of the molten metal and of ejecting the superliuous metal remaining in the cylinder after the completion of the casting operation, as and for the and of being Withdrawn from the cylinder While the molten metal is being introduced into the latter, a piston capable of sliding in the cylinder' and of ejecting the superfluous metal remaining in the cylinder after the casting operation and means for moving the piston in front of the gates of the moulds.

While the vmolten metal is being introduced into the cylinder and for allowing it to rest on the bottom of the cylinder during the application of pressure by the plunger, as and for the purpose set forth.

4. A casting machine comprisino' in combination a cylinder capable of being lilled with molten metal, lateral openings in the Walls of the cylinder, a plurality of moulds capable of being moved so as to bring their gates up against the said lateral openings, a plungercapable of sliding axially in the cylinder for producing the casting pressure and of being` Withdrawn from the cylinder While the molten metal is being introduced into the latter, a piston capable of sliding in the' cylinder for ejecting the superfluous metal remaining in the cylinder after the casting operation and means for rotating the piston about its axis as it rests on the bottom of the cylinder for closing the gates of the moulds during the filling of the cylinder with molten metal and for opening the gates during the casting operation, as and -for the purpose set `forth.

5: A casting machine comprising in combination a cylinder .capable of being filled with molten metal, 'lateral openings in the Walls of the cylinder, a plurality of moulds capable of being moved so as to bring their gates up against the said lateral openings, a plunger capable of sliding axially in the cylinder for producing the casting pressure and of being Withdrawn `from the cylinder while the molten metal is being introduced into the latter, a piston capable of sliding in the cylinder for ejecting the superfluous metal re maining in the cylinder after the casting operation, means for rotating the piston about its axis as it rests on the bottom of the cylinder, depressions on the upper face of the piston, extending from the cylindrical edge upwards and inwards towards the middle thereof and capable of being brought by the rotation of the piston inl alignment with the gates of the moulds for establishing communication with the interior of the cylinder during the casting operation and out of alignment with the gates for blocking the said gates while the cylinder is being filled -with the molten metal, as and for the purpose set forth.

6. A casting machine comprising in combination a cylinder capable of being filled with molten metal, lateral openings in the Walls of the cylinder, a plurality of moulds capable of being moved so as to bring their gates up againstthe said lateral openings, a plunger capable of sliding axially in the cylinder for producing the casting pressure and of being Withdrawn from the cylinder While the molten metal is being introduced into the latter, a guided cross head piece for supporting the plunger, a slot in the said cross head piece, a piston capable of sliding in the cylinder, for ejecting the superfluous metal remaining in the cylinder afterthe casting operation, a piston rod for supporting the said piston extending through the said slot, a driving member on the said piston rod, means for turning the piston rod for causing the driving member to pass through the said slot during the motion of the cross head piece and plunger before the casting operation and for causing the driving member to engage across the slot after the casting operation, whereby during the upward motion of the cross head piece and plunger for opening the cylinder the piston is caused to take part in the said motion, as and for the purpose set forth.

7. A casting machine comprising in combination a cylinder capable of beinglilled with molten metal, lateral openings in the walls of the cylinder, a plurality of moulds capable of being moved so as to bring their gates up against the said lateral openings, a plunger capable of sliding axially in the cylinder for producing the casting pressure and of being Withdrawn from the cylinder While the molten metal :is being introduced into the latter, a piston capable of sliding in the cylinder for ejecting the superfluous metal remaining in the cylinder after the casting operation, means kfor rotating the piston about its axis as it rests on the bottom of the cylinder for closing the gates of the moulds during the filling of the cylinder with molten metal and for opening the gates during the casting op- 'eration and raised edges on the face of the JOSEF PQLK. 

